Data for: Strips of prairie vegetation placed within row crops can sustain native bee communities

This data demonstrated how strips of reconstructed native prairie vegetation placed in corn and soybean fields effectively sustained bee communities and restored important pollinators. The study was conducted in 2016 and 2017 at four paired comparison sites (i.e., 8 crop fields) in Iowa, USA, located in Guthrie (site 1), Linn (2), Marshall (3), and Pottawattamie (4) counties. Sites were situated in landscapes dominated by intensively managed agricultural fields producing corn and soybean. At each paired study site, bees were sampled in two crop fields. The first field was 100% crop production and provided the control treatment. The second field also was used for crop production, however, 10-12% of the field area had been seeded with a diverse mix of native perennial prairie species within strips planted on the contour; this type of field represented the strip treatment. Crop identity was the same at each site for strip and control fields, but the crop differed between locations; site 1 produced corn in 2016 and soybean in 2017, sites 2 and 4 produced soybean in 2016 and corn in 2017, and site 3 produced corn in both years. Bees at all sites were sampled four times each year, with approximately one month between samples, from late May until late August.

We found that increases in both the abundance and diversity of floral resources in strips of native prairie vegetation within agricultural production fields greatly and positively influenced the bee community. The benefits to the bee community were important for both common and uncommon species and the effect may be strongest early in the season. Using networks of co-occurrence between plant and bee species, we were able to identify potentially keystone resources that can be used to support native bees. When we evaluated the effect of reconstructed prairie strips on bees in the context of the surrounding landscape, we found that these conservation practices had positive effects on bees in agriculturally-dominated areas and that these effects were detectable in low to high complexity landscapes with 8-69% natural habitat. In landscapes dominated by crops with few pollen and nectar resources the inclusion of native prairie strips can buffer the decline of bees and effectively increase bee abundance and diversity.